1. Field of the Invention
The objective of the invention relates to a method and a device for cleaning the undersurface of footwear and the wheels of shopping trolleys, wheelchairs, perambulators and similar items in the entrance areas of frequently used public facilities such as shopping centers, administrative and commercial buildings, healthcare centers or other complexes in public use and with predefined standards of cleanliness.
In supermarkets and stores providing non-prepackaged foods (sausage, meat, dairy products, fruit and vegetables on display), there exist requirements of cleanliness which include the floors. It has to be ensured that no dirt from outside the building reaches displays of non-packaged foods. The greatest source of dirt in this case is from. customers entering shopping centers with their trolleys from the parking lot.
The operators of such markets are obliged to install particularly standardized cleaning mats in the area of the entrance. The said mats are supposed to remove and absorb the dirt from footwear and wheels while the customers push their trolleys over them.
Numerous embodiments of mats of this kind are known. They can be manufactured simply and at reasonable cost and obtained in practically any dimensions wanted. The low constructional height of the mats is also advantageous since they can be laid out over large surfaces of even flooring without being perceived as a hindrance by those entering.
In cases of rain and snowfall, however, it is clearly visible that these measures are not adequate to meet the floor cleanliness required. The mats usually installed in the entrances of supermarkets are capable of soaking up about four liters per square meter. The absorption capacity of such mats is already exhausted after 30 minutes if customer traffic is heavy and the weather conditions unfavorable. Subsequently they are no longer a barrier, and dirt and water are borne in and spread around the entire shopping center by the footwear of the public and the wheels of the shopping trolleys.
Although the markets usually make an effort to master the situation by deploying cleaning staff, this is not always possible, depending on the staff available, very cost intensive, and ultimately not effective either.
In addition to the above, the cleaning mats laid out are unattractive from n aesthetic point of view since the impression of a dirty and soaking wet mat has a repellent effect on the public and as a rule displays an undesirable contrast to the other design of the premises.
For the purpose of increasing the absorption capacity of dirt and moisture, cleaning devices with rotating cylindrical brushes or fixed or moveable rows of brushes are known. A supporting structure of parallel rods or belts, into which the upright bristles are clamped or glued, is arranged in a frame structure.
Since devices of this kind have a certain structural height they are usually let into recesses in the floor constructed for this very purpose in the entrance area of the building and wherein the upper edge of the brushes is almost flush with the floor level. The cleaning brushes in such cases may be fixed, free running or driven by a motor.
Since the relatively stiff bristles are also capable of penetrating the footwear sole patterns, they clean more intensively than mats. In addition to the above, the intermeshing of adjacent rows of brushes also introduces a cleaning effect by; stripping off any material adhering to the bristles.
In order to avoid the accumulation of dirt in the underlying recess, dirt and water collecting basins are frequently arranged in the recesses underneath the cleaning brushes.
Because of the self-cleaning effect of the brushes and the uptake capacity of the collecting basin, cleaning devices of this kind clearly have a longer operational period. The dirt collected only needs to be removed after longer time intervals.
2. Description of the Related Art
In order to provide additional support for brush cleaning at the entrance to commercial buildings with a high frequency of visitors and higher cleaning requirements, Patent No. DE 4447498 A1 proposes a footwear sole cleaning device based on rotationally moving belts of brushes wherein the cleaning brushes are automatically cleaned by counter brushes acting on them during operation.
The said facility consists of a large number of motor driven cleaning brushes running parallel to one another transverse to the direction of the people passing through. To achieve the removal of adhering soilage the brush belts are engaged by fixed counter brushes or rotating drums of brushes outside the level walked on.
The measures proposed undoubtedly improve the cleaning effect and prolong the servicing intervals.
A disadvantage of the aforesaid cleaning device in the nomenclature of the independent claim is that they are not suitable for application in sales amenities designed to be visited with a shopping trolley. The reason is that trolleys can only negotiate such devices with difficulty since the mainly small wheels tend to become jammed in the interspaces between the brush carriers.
A device for cleaning wheels is known from Patent No. WO 95/23715. The said device consists of a platform with a trough shaped recess reached via a ramp. A cleaning device consisting of brush segments is arranged at the base of the recess, whereas the sloping sides exhibit pairs of rollers opposite one another., At least one of the rollers is motor driven in order to set the wheels in rotation during the cleaning process.
The remedy proposed above, however, fails to provide any criterion for cleaning the wheels of shopping trolleys, particularly at the entrance to or inside highly frequented commercial buildings, since the device is relatively difficult to negotiate and the actual cleaning process requires the trolley to stand still. In addition to the above, the simultaneous cleaning of footwear is not possible.
The chains of stores are striving for a larger throughput of customers. The aforementioned effective cleaning devices can only be negotiated in a time consuming way however. They limit the throughput of customers and ultimately the turnover.
The invention was thus based on the objective of setting up a method as well as a device which does not exhibit the aforementioned disadvantages and reveals an efficient cleaning effect of long endurance, particularly at times of unfavorable weather conditions and intensive use.
The objective is achieved according to the invention by a method and device such as classified in independent claims 1 and 12.
Further advantageous developments of the invention are recorded in the subordinate claims.
The advantage of a long sustainable efficient cleaning effect is achieved by the use of a cleaning mat designed as a continuous loop running between at least two guide rollers. The mat serves at least partially as a public access surface in the accessible section, absorbing solid and liquid soilage, the said soilage being subsequently removed again by mechanical, pneumatic, thermal or other suitable treatment in a spatially remote section running in the reverse direction.
A cleaning device with a rotationally moving cleaning mat is let into an opening in the floor of the entrance area of the building in such a way that a public access surface flush with or slightly lower than the surrounding floor results, while the soiled mat is subjected to reconditioning processes within the floor opening in the section running in the reverse direction on the opposite side from the walk-in surface.
The cleaning facilities comprise facilities for removal of the dirt trodden in and such for expulsion of the liquid absorbed.
Mechanical, hydraulic and/or pneumatic mechanisms actuate on the mats for the removal of the dirt and dirty water adhering to the surface. As examples of the former within the meaning of the invention are blades for scraping off dirt or cleaning brushes, the latter are to be understood as belts of brushes sweeping back and forth or rotating cylindrical brushes, beating or vibration equipment, suction nozzles or guide rollers producing meandering or zigzagging motion of the mats. Cleaning with liquids can be carried out by continuous or intermittent spraying of the liquid from nozzles or by contact with a dip bath designed such that at least the pile of the mats is temporarily immersed in the liquid.
Water, which may contain detergents or other additives, serves as the cleaning liquid.
Arrangements of nozzles using compressed air to blow dirt and moisture out of the carpet pile are to be understood as pneumatic actuators. Simultaneous subjection of the path to ultrasound oscillation can further stimulate the process of dirt and moisture deposition.
Any moisture remaining in the mat after completion of the aforementioned reconditioning processes is subsequently expelled thermally by flows of warm air, radiation or the effects of microwaves.
In such applications where preferably dry, fine and non-adhesive dirt particles occur, cleaning of the pile on an electrostatic basis is also possible. The dust particles are drawn out of the mat, electrostatically charged by suitable means, by passage close to a counterelectrode.
In order to increase the absorption capacity of dirt and moisture as well as improving its appearance, the clean dry mat can subsequently be passed through equipment such as a rotating cylindrical brush to re-upright and loosen up the flattened fibers.
To offset the expansion and shrinkage processes which occur during wetting and drying the mat, one or more tensioning rollers can be arranged at a suitable position, for example in the area of the cleaned and dried mat.
In terms of one embodiment of the invention, at least one of the guide or drive rollers in the region below the floor is designed as a tensioning device.
When the public access surface is walked on or otherwise passed over, the whole weight of the visitors and trolleys is transmitted to the cleaning devices via the mat. It thus becomes necessary to support the mat in the region of the public access surface in such a way that it does not sag or become overloaded.
Since the cleaning mat moves with a barely perceptible speed in the majority of applications, it can glide over a supporting plate firmly mounted in a frame or attached to the substructure in the entire area of the public access surface in the simplest case. The forces induced by walking through can then be diverted into the substructure via this platform and the device frame. In order to transfer driving torque to the cleaning mat, the margins of the same are fitted with an additional layer exhibiting profile or perforation features which are coupled via drive elements to at least one of the guide rollers.
An alternative embodiment of such a supporting system preferred according to the invention makes it possible to interconnect the function of supporting the rotationally moving; mat in the area of the public access surface with the function of transporting the said mat in an advantageous manner. According to the invention this is achieved with the aid of a webbed belt conveyer.
A belt conveyer runs between the said guide rollers, The surface of the belt is coated with an anti-slip finish. The belt conveyer and cleaning mat run parallel in the region of the guide rollers and the carrying run. The mat supports itself on the belt as a result of the effects of the tensioning device and those of the loads occurring.
The belt simultaneously transmits its forward drive via the anti-slip coating to the mat and actuates the same.
In a further embodiment of the invention, the transport belt is a link conveyer made up of articulated interlocking flat links.
In yet another embodiment, the belt consists of parallel slats arranged transversely to the transport direction and attached to toothed belts or roller chains.
The circulating belt conveyer loop can either slide fully or in sections on or inside tracks.
In a further development of the invention the belt may be a reinforced elastomeric belt which is either detachably fastened to the cleaning mat using a Velcro closer or non-detachably fastened using adhesive or similar means. Clearing mat and belt conveyer are thus fused together to a functional unit In this integrated structurexe2x80x94hereinafter referred to as the cleaner sliding beltxe2x80x94the belt conveyer takes over the forward drive and tractive forces and the glued on or flocked pile the adsorption of dirt particles and moisture. The adhesive interlayer fixing the pile simultaneously serves to subdue the noise of footsteps and sound emission from the drive and cleaning units in the region below the surface.
At least one of the guide rollers is under drive, preferably in the direction of the loop in front of the public access surface. If the forward drive forces are transmitted via friction, at least the drive roller has to be covered with an anti-slip coating, for example a rubber sheath.
Alternatively of course, the band conveyer can also ran over an additional drive roller or driving pinion located at a suitable position.
Electronic control fitted with internal; and external sensors is used for optimal operation of the cleaning device.
The integrated control equipment has programs for summer and winter operation as well as a clock for busy and less busy times of day.
The internal sensors measure the dirt and moisture contents of the mat leaving the public access surface. Their output signals control the forward drive speed and the intensity of cleaning and drying the mat.
The eternal sensorsxe2x80x94positioned outside the buildingxe2x80x94register the current weather conditions by measuring the humidity, the degree of precipitation and the temperature. The output signals are relayed to or override those of the other sensors.
The dirt and dirty water occurring in the cleaning device can either be accumulated in the collecting basins or discharged through an outlet in the floor.
If collecting basins are used, the same can be equipped with level indicators to inform the staff about the state of the cleaning device and if necessary warn them that an emptying process is due.
The pedestrian safety of the joint between the cleaning device let into the floor and the surrounding floor itself is ensured by edging strips. At the same time, the strips on the long edges serves to hold the mat edges in place on the transport belt in addition to guiding the trolley wheels.
Cap profiles which can be trodden on overlap the guiding mechanisms of the mat at the long edges opposite each other or are flush mounted adjoining them. To ensure unproblematic passage on and off they are beveled off towards the mat in the first case. The aforementioned cap profiles on the long and short sides are hinged to or can be dismounted from the frame structure and serve as at least part of the removable covers for maintenance work.
The entire cleaning device is integrated in a frame structure and is let into and fixed in a properly prepare,d and dimensioned opening in the floor as an installation unit in the entrance area of the building. A preferred embodiment concerns the concept of modular construction. The individual components, split up according to their Functions as drive, guide and cleaning units, can be assembled together in any way at all and thus permit adaptation to the requirements of different applications. The said concept leads to universal applicability of the cleaning device in terms of the invention far beyond the range of the sales amenities.
The cleaning device according to the invention possesses a practically unlimited absorption capacity since a freshly cleaned and dried foot mat is repeatedly made available. The saturation with dirt and water occurring in conventional mats does not occur even after prolonged operational periods. For this reason, a good, uniform and long term sustainable cleaning effect is warranted. This service friendly attribute saves the costs of staff kept on standby for cleaning purposes or for replacing the mats laid out.
Due to the at least approximately flush fitting to the surrounding floor, the mat can be very easily overcome by shopping trolleys, perambulators, wheelchairs, buggies etc, and thus presents no limitation to the customer throughput in sales amenities which are strongly frequented and can only be entered with shopping trolleys.
The invention is not, however, restricted to sales amenities. It can also be applied in front of or inside any kind of commercial building or other administrative institutions with considerable Public traffic. Since cleaned mats with brushed up pile are constantly delivered during business hours, they always present an attractive appearance.
With regard to changing in situ conditions of use, the modular type of construction provides a high degree of flexibility by retrofitting work. individual modules can be exchanged or supplemented with little effort.
Together with preventing the input of dirt and moisture, the invention also offers an opportunity for improving the hygiene in premises equipped with it. A further development of the invention is thus in mind wherein the rotationally moving mat is not only constantly freed of adhering dirt and moisture, but can be treated further. Such further treatment may on the one hand consist of enhancing the cleaning effect by spreading a detergent. On the other hand, the mat can be impregnated with a disinfectant liquid after completion of the cleaning phases. The latter makes it possible to reduce the input of germs on the soles of shoes or the wheels of trolleys along with the dirt in medical centers such as hospitals, or in research and manufacturing complexes with strict cleanliness demands.
Antistatic agents can be applied to prevent or remove electrostatic charges, for example in clean rooms for the production of electronic components.
Application of the foregoing agents can be carried out by any of the known methods by rotating brushes or aerosol spray equipment.
Installation of the cleaning device is not restricted to horizontal floors it can also be integrated in a ramp for trolleys and wheelchairs.
Equipping or combining the device with modern measurement, management and control instruments permits a great variety of operational modes.
Thus various modes can be pre-chosen for busy or less busy periods, for summer or winter operation etc.
In addition to the above, internal sensors permit operation dependent on the actual degree of dirt contamination of the cleaning mat, whereas the switching in of external sensors on sudden weather fluctuations (unexpected strong thundery showers or similar) permits immediate reaction prior to overcharging of the mat.